This invention relates to unit dose compositions for cleaning laundry, in particular to unit dose laundry liquid detergents comprising sequestrants and incorporated in water-soluble pouches.
Cleaning/care compositions come in a number of product forms, such as granules, liquids, tablets, and pouches each form having its own advantages and disadvantages.
Recently, water-soluble pouches containing washing, cleaning or care actives have become popular. In general, the pouches comprise a liquid or powder detergent composition surrounded by a water-soluble film, such as polyvinyl alcohol. These products have the advantage that they are convenient to dose, easy to handle and cause little mess in comparison with traditional detergent forms. However, they are difficult to make economically and have some limitations such as a tendency to leak or to leave residues, for example residues derived from the pouch material incompletely dissolving or dispersing.
The pouched cleaning composition must be able to disintegrate quickly and completely without residue being left in the drawer, in the wash drum, or on laundered clothing. Prior art liquid unit dose laundry compositions have shortcomings with respect to meeting one or more of these stringent requirements.
One approach to improving solubility and/or to reducing residue is to decrease the level or remove completely from the liquid detergent formulation, the detergent ingredients that adversely affect solubility when they come into direct contact with the surrounding pouch material. Another approach is to formulate only very soluble and generic detergents, e.g., liquids entirely free from particulate matter and from challenging ingredients. Yet another solution is to focus on pouch materials, however this latter option restricts the possibility of using a wide variety of commercially available pouch materials.
WO01/79417 relates to a unit dose composition hindering the formation of lactones in pouch walls when these are made from a copolymer, by pH adjustment. EP 1 120 459 discloses a laundry detergent comprised of a substantially anhydrous isotropic liquid detergent formulation packaged in a water-soluble film, the liquid detergent comprising anionic surfactants and soap, and is said to be suitable for use when high foam levels are required. WO01/79416 relates to a water-soluble package in the form of a plastic envelope made by horizontal or vertical filling with a non-aqueous liquid detergent having a high or a low viscosity. U.S. Pat. No. 4,973,416 describes a clear, stable and isotropic aqueous liquid laundry detergent in a unit dosage form having an organic neutralization system, the detergent being formulated in a package comprising a water-soluble film-forming material.
As seen above, the pouched cleaning composition must be able to disintegrate quickly and completely in order to avoid residue being left in the drawer, in the wash drum or on the washed garments. Prior art compositions often do not dissolve as rapidly or as fully as desired. Furthermore the compositions known in the art do not effectively address the technical problem of how to make a liquid unit dose product for laundry, providing superior cleaning performance.
Hence, an object of the present invention is to provide pouched cleaning compositions that provide superior cleaning performance, demonstrate excellent dissolution and avoid residues. It has been found that some builder and chelants, i.e. builders/chelants free of C8-22 alkyl or alkenyl chains, are essential to obtain such superior cleaning performance. However, such detergent ingredients may cause dissolution and residues problems. Therefore, it is an object of the present invention to provide a pouched cleaning composition incorporating builders and/or chelants, especially those that sequester transition metals in soils or wash-water for improved cleaning, while avoiding the dissolution and residues problems. Another object of the present invention is to provide a method to select the appropriate sequestrants and/or the appropriate physical forms under which they are suitable for use in pouched cleaning compositions.
It has now surprisingly been found that the pouched cleaning compositions of the present invention demonstrate better solubility and/or lower residues formation than do otherwise identical products wherein such sequestrants (builders/chelants free of C8-22 alkyl or alkenyl chains) are soluble in the liquid composition. The compositions of the present invention also demonstrate better cleaning performance that otherwise identical products wherein such sequestrants have been removed or their levels greatly diminished.
The present invention relates to a pouched cleaning composition wherein the pouch is constructed from a water-soluble film and contains a liquid composition comprising:
(a) less than 5% by weight of the liquid composition, of water;
(b) an anionic surfactant;
(c) at least 0.5% by weight of the liquid composition of a builder/chelant free of C8-22 alkyl or alkenyl chains (herein referred to as sequestants); and
is characterized in that less than 0.3%, preferably less than 0.2%, more preferably less than 0.1% by weight of the liquid composition, of said sequestrants is dissolved in said liquid composition.
The present invention further relates to a process for making a cleaning composition comprising:
(a) Formulating a liquid detergent with such a sequestrant being less than 0.3%, preferably less than 0.2%, more preferably less than 0.1% by weight of the liquid composition, soluble in said liquid composition; and
(b) Incorporating such liquid detergent within a water-soluble pouch material.
Such process produces a pouched cleaning composition demonstrating good cleaning performance while preventing the pouch material from being insolubilized by the sequestrant.
The present invention also relates to the use of such sequestrants in a pouched cleaning composition for better cleaning performance and better solubility of the pouch while avoiding the formation of residues. The present invention also relates to methods of fabric treatment using such a composition.
The invention demonstrates improved cleaning as compared to otherwise identical compositions not having such sequestrants, and secures excellent low residue dissolution of the water-soluble pouches in automatic washing machines in the presence of heavy-duty liquid laundry detergent. This includes such dissolution at low wash temperatures (e.g., 5-30xc2x0 C.) and/or low water levels (as in wool cycles or crease cycles) and/or short washing times (e.g., 5-50 min.) and/or in the presence of large amounts of laundry.